Spunbond fabrics produced with homopolymer polypropylene (“HPP”) are well known in the industry. These fabrics though, possess certain qualities that are not ideal. Specifically, spunbond non-woven fabrics comprising HPP are subject to certain processing limitations that affect the ways in which these fabrics may be handled when producing a finished product.
Typical tactics used to modify the physical characteristics of a given HPP spunbond non-woven to make it more workable for a given application include increasing or decreasing a variety of parameters, alone or in various combinations. Parameters that may be modified include calender bonding temperature, calender pressure, calender bonding area, fiber diameter, and the weight of the fabric per unit area (basis weight). Even, however, when each of the above described properties is optimized for a given application, the HPP spunbond non-woven is still subject to certain inherent limitations that cannot be overcome, optimization notwithstanding.
Two of the most difficult issues to address with HPP spunbond non-woven fabrics are the limited fabric extension at the ultimate tensile strength and the nature of the fabric extension under load.
In view of these deficiencies, there is a need for novel spunbond non-woven products exhibiting improved force-extension relationships as compared to those of standard HPP spun bond non-woven fabrics.